it is correct.
i don't know what bluetooth devices you've used, but they don't sound like very good ones.
what you describe is definitely not representative of bluetooth, which is *extremely* reliable.
headsets can work at fairly long distances, including between floors in a house, which is something not realistic with a cable, and would have losses due to distance if it was.
analog headphones are actually *less* reliable, many times requiring wiggling the plug to get a good connection, an issue that *can't* happen with bluetooth.
that's a different issue, except that you are exposed to far higher rfi from many other sources, namely a cellphone held to your head for a phone call, as well as tv/radio transmitters, etc.
no they don't normally have a 90 degree connector.
almost all headphone plugs protrude and can torque. it's a very common failure mode.
it's not far fetched at all.
an analog headphone jack is literally a hole in the phone where liquid and dirt can ingress.
although it's possible to make it water resistant, that is a lot more difficult than if there was no hole at all, which should be obvious.